1. Field of the Invention
This invention relates to a method of sensing malfunctions of a water supply system employed in a boiler system and an apparatus thereof.
2. Description of the Prior Art
Generally, in a boiler system, heating water is heated in a heat exchanger of a boiler heated by heat generated by combustion of fuel such as a gas, petroleum or the like. The heating water heated in the heat exchanger is discharged to a heating pipeline system through a discharge pipe by the operation of a circulation pump of the boiler. Consequently, the indoor temperature of a heating place such as a house, a building or the like equipped with the heating pipeline system is elevated. The heating water in the heat exchanger is supplied from a water tank, and the heating water discharged from the heating pipeline system after heating the heating place returns to the water tank through a heating water return pipe. That is, the boiler system forms a heating water circulation circuit by the circulation of the heating water through the water tank, the heat exchanger, and the heating pipeline system.
The water tank supplements the heating water to the pipeline circuit when the heating water in the heating water circulation circuit of the boiler system is insufficient by the natural evaporation of the heating water therein. Furthermore, the water tank exhausts an increased or reduced pressure of the heating water in the pipeline circuit to an exterior therethrough, which is developed as the heating water volume in the pipeline circuit is varied by the temperature variation of the heating water.
Therefore, it is important in a boiler system to maintain an appropriate water level in the water tank.
FIG. 1 is a schematic diagram for showing a water supply system of the prior art.
As shown in FIG. 1, the water supply system 100 is provided with a water tank 110. The water tank 110 is provided with an overflow pipe 160 at an inner side therein. The overflow pipe 160 drains out the superfluous water in the water tank 110. A heating water discharging pipe 170 is connected with the water tank 110 for discharging heating water in the water tank 110 into a heat exchanger (not shown) therethrough. The water tank 110 is provided with a heating water return pipe(not shown) for returning the heating water from a heating pipeline system(not shown) to the water tank 110. The water tank 110 is connected with a water source(not shown) via a supplementary water pipe 120. A supplementary water valve 130 is installed at the supplementary water pipe 120 to be able to control a supplying of supplementary water from the water source to the water tank 110. The supplementary water valve 130 is electrically connected with a controller 140, and controlled by the controller 140. The controller 140 is electrically connected with a water level sensor 150. The water level sensor 150 is installed in the water tank 110, and senses a water level of the heating water in the water tank 110. The water level sensor 150 includes a float 151, a rod 152, and a magnetic switch 153. The float 151 moves up and down in accordance with changes of the water level in the water tank 110. One end of the rod 152 is connected with the float 151, and a magnet (not shown) is installed at the other end of the rod 152. The magnetic switch 153 is mounted on an upper inside wall of the water tank 110, and is turned on or off in response to a magnetic force generated from the magnet. That is, when the magnet approaches within a predetermined distance from the magnetic switch 153, the magnetic switch is turned on by the magnetic force of the magnet, and a turn-on signal generated by the magnetic switch 153 is outputted to the controller 140.
When a turn-off signal is inputted from the water level sensor 150 to the controller 140, the controller 140 controls the supplementary water valve 130 to be opened, such that supplementary water is supplied to the water tank 110 through the supplementary water valve 130. To the contrary, when the turn-off signal is inputted to the controller 140, the controller 140 causes the supplementary water valve 130 to close to cut off the supply of the supplementary water to the water tank 110. Therefore, the water level in the water tank 110 is kept at a constant level.
However, in the water supply system, when the water level sensor 150 or the supplementary water valve 130 is out of order, since the water supply system does not sense malfunctions of the water level sensor 150 and the supplementary water valve 130, the heating water in the water tank 110 is insufficient or the supplementary water is continuously supplied to the water tank 110.
For the foregoing reasons, there is a need for a method which can sense the malfunctions of a water supply system and an apparatus which can perform the method.